Devices, systems, and methods for protecting healthcare workers from airborne pathogens

ABSTRACT

A method of removing exhaled material from a medical procedure field adjacent to a subject&#39;s nose and mouth. In some embodiments the method includes the steps of placing an isolation barrier at least partially surrounding the subject&#39;s nose and mouth to define the medical procedure field; controlling air flow into the medical procedure field with the isolation barrier; and evacuating air from the medical procedure field at an air evacuation rate greater than or equal to the subject&#39;s respiratory minute volume. The invention also provides a system for creating an isolated medical procedure field around a subject&#39;s nose and mouth.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 119 of U.S. PatentAppln. No. 63/015,429, filed Apr. 24, 2020; U.S. Patent Appln. No.63/019,986, filed May 4, 2020; and U.S. Patent Appln. No. 63/021,033,filed May 6, 2020, the disclosure of each of which is incorporated byreference.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference in their entirety to the sameextent as if each individual publication or patent application wasspecifically and individually indicated to be incorporated by reference.

BACKGROUND

This invention relates generally to the field of personal protectionequipment (PPE) and more specifically to a new and useful system forprotecting physicians and healthcare workers from airborne,aerosol-borne and particle-borne pathogens during medical examinationsand medical procedures within or through the nose and/or mouth.Physicians and other health care professional performing procedures inand around a subject's airway (e.g., the nose, the mouth) can be exposedto air-borne pathogens carried by droplets and particles from thesubject's exhaled breath, particularly if the subject sneezes or coughs.Some diagnostic and therapeutic procedures performed in and around thenose and mouth can increase the velocity of air in the subject's airwayand thereby increase the creation and dissemination of droplets andparticles in the subject's exhaled breath. Masks and respirators, suchas an N95 respirator, can block such particles, but they can also blockaccess to the nose and mouth, thereby preventing the performance ofdiagnostic and therapeutic procedures in the nose and mouth.

The outbreak of the COVID-19 pandemic, caused by the SARS-CoV-2 virus,has the world, and specifically healthcare workers and governingauthorities, reevaluating personal protective equipment (PPE), and theirassociated guidelines for utilization, to slow the spread of the virusand to prepare for similar pandemics like this in the future. Pathogens,including the SARS-CoV-2 virus, the Ebola virus, bacterial, fungi,prions, micro-organisms and other pathogens are known to spread throughthe air by means of convective transport either alone (as in the case offungal spores, for example) or attached to or entrapped by aerosols(such as those produced when a person sneezes or coughs, for example),airborne particles (such as dust, for example), or other transportmedia.

Since the emergence of the SARS-CoV-2 virus in late 2019, manyauthorities have mandated that everyone should cover their nose andmouth (with PPE such as with an N95 type respirator) to reducetransmission of air-borne pathogens. This use of PPE has been shown tohelp reduce the spread of the virus, however there are many instanceswhere continuous coverage of the nose and mouth is impractical, such asmedical procedures within the airway, procedures in the uppergastrointestinal (GI) tract, and/or dental exams, surgeries orprocedures. In these examples, the person being examined (the subject)removes their mask, and healthcare workers and physicians get withininches of the subject's airway to treat or examine the subject.

It is well known in the medical and healthcare fields that normal humanrespiration can emit particulates, pathogens and/or aerosols from thenose and mouth. During normal breathing and talking these emittedparticulates, pathogens and aerosols can travel significant distance,often measured in feet or tens of feet, from an individual. Duringepisodic respiration events like coughing, sneezing, hiccupping,burping, clearing the throat, gasping or heavy breathing patterns, etc.these particulates, pathogens and/or aerosols may be more abundant andtravel farther from a person. Furthermore, tissue manipulation and somemedical interventions and procedures (such as abrasion type procedures)may cause these particulates, pathogens and/or aerosols to become moreabundant and travel farther from the subject. Any of the above mentionedrespiratory and medical events can result in a healthcare worker,medical staff, other subjects and other individuals to become exposed toan infectious agent or pathogen, and/or result in contamination of aroom, equipment, furniture or other objects, even while wearing existingPPE.

Physicians from Stanford University reported on instances of infectiouspathogens being spread to physicians and healthcare workers duringendonasal endoscopic surgeries in their letter of precaution in theJournal of Neurosurgery. Based on the information presented in theletter, physicians started only performing only urgent/emergentsurgeries and requiring the utilization of a powered air purifyingrespirator (PAPR) if endonasal surgery cannot be postponed in a COVID-19positive subject. A powered air purifying respirator is a piece ofpersonal protective equipment (PPE) that protects the individualhealthcare worker wearing the piece of equipment by pulling air in,filtering the air and blowing the filtered air over the individual. ThisPPE has been shown to be effective, but the need to have this piece ofequipment for every individual in the room makes this not a long termviable solution. Since this letter of caution was published, additionalphysicians have reported on continued investigations on theaerosolization of pathogens and particulates from a subject duringvarious airway procedures. Physicians from the Massachusetts Eye and EarInfirmary, the Harvard Medical School, and the Massachusetts GeneralHospital (all in Boston, Mass.) reported on the aerosolization riskduring endonasal instrumentation.

Physicians in the above-mentioned report identified that aerosolizationof particulates during endonasal procedures is a risk specifically dueto sneezing as well as due to several common surgical procedures. Theyalso noted that a use of a barrier significantly reduced the spread ofthe aerosols. “Endonasal Instrumentation and Aerosolization Risk in theEra of COVID-19: Simulation, Literature Review, and Proposed MitigationStrategies” (reference: https://doi.org/10.1002/alr.22577) isincorporated in its entirety by reference.

The COVID-19 pandemic has brought awareness to the forefront that thereremains an urgent need for the development of new devices, systems, andmethods to prevent and manage the release of subject-generated air-bornepathogens, particulates, and aerosols in medical and healthcareenvironments while still allowing diagnostic and therapeutic proceduresto take place in and through the nose and mouth. What is needed is abarrier to air-borne particulates emanating from a subject during adiagnostic and/or therapeutic medical procedure performed in and aroundthe subject's nose and mouth.

SUMMARY OF THE DISCLOSURE

One aspect of the invention provides a method of removing exhaledmaterial from a medical procedure field adjacent to a subject's nose andmouth. In some embodiments, the method includes the steps of: placing anisolation barrier at least partially surrounding the subject's nose andmouth to define the medical procedure field; controlling air flow intothe medical procedure field with the isolation barrier; and evacuatingair from the medical procedure field at an air evacuation rate greaterthan or equal to the subject's respiratory minute volume. In someembodiments, the evacuating step includes the step of evacuating airfrom the medical procedure field at an air evacuation rate greater thanor equal to 10 liters/minute.

In some embodiments, the method includes the step of maintaining anegative pressure of 0.14-68 cm H₂O within the medical procedure field.In some such embodiments, the method also includes the step ofmaintaining a negative pressure within the medical procedure field whenthe subject coughs or sneezes.

In some embodiments, the method includes the step of filtering airevacuated from the medical procedure field. Some such embodiments mayalso include the step of returning filtered air to the medical procedurefield.

In some embodiments, the placing step includes the step of placing theisolation barrier against a face of the subject, the medical procedurefield being bordered by the isolation barrier and the subject's face.Some such embodiments also include the step of establishing a sealbetween the isolation barrier and the face. In embodiments in which theisolation barrier further includes a drape, the placing step may alsoinclude the step of placing the drape against a neck of the subject.

Another aspect of the invention provides a method of performing aprocedure in or around a subject's nose or mouth. In some embodiments,the method includes the steps of: evacuating air from within anisolation barrier at least partially defining a medical procedure fieldadjacent to the subject's nose and mouth at an air evacuation rategreater than or equal to the subject's respiratory minute volume, theisolation barrier controlling air flow into the medical procedure field;and accessing the subject's nose or mouth within the medical procedurefield to perform the procedure.

In some embodiments, the evacuating step includes the step of evacuatingair from the medical procedure field at an air evacuation rate greaterthan or equal to 10 liters/minute.

Some embodiments add the further step of maintaining a negative pressurewithin the medical procedure field. In some such embodiments, the anegative pressure of 0.14-68 cm H₂O is maintained within the medicalprocedure field. Some embodiments maintain a negative pressure withinthe medical procedure field when the subject coughs or sneezes.

In embodiments in which the isolation barrier has a transparent portionthrough which the medical procedure field can be viewed, the viewingstep may include the step of viewing the subject's nose or mouth throughthe transparent portion of the isolation barrier.

Some embodiments include the further step of filtering air evacuatedfrom the medical procedure field. In some such embodiments, the filteredair is returned to the medical procedure field.

In some embodiments, the accessing step includes the step of insertingan instrument through a port in the isolation barrier. In some suchembodiments, the inserting step includes the step of inserting theinstrument through a seal of the port.

In embodiments in which the isolation barrier includes a drape, theaccessing step may include the step of reaching beneath the drape.

Yet another aspect of the invention provides a system for creating anisolated medical procedure field around a subject's nose and mouth. Insome embodiments, the system includes: an isolation barrier adapted toat least partially surround the subject's nose and mouth to form themedical procedure field, the isolation barrier having an air exit port;and an air mover operatively connected to the air exit port andconfigured to remove air from the medical procedure field at an airevacuation rate greater than or equal to the subject's respiratoryminute volume. In some embodiments, the air evacuation rate is greaterthan or equal to 10 liters/minute. In some embodiments, the air mover isfurther adapted to cooperate with the isolation barrier to maintain anegative pressure within the medical procedure field.

In some embodiments, the isolation barrier has a seal adapted to sealagainst the subject's face. In some embodiments, the isolation barrierhas a drape adapted to be placed against the subject's neck.

In some embodiments, the isolation barrier has an instrument access portarranged and configured to permit a user to insert an instrument to thesubject's nose or mouth. In some such embodiments, the instrument accessport has a seal adapted to seal around an inserted instrument.

In some embodiments, the isolation barrier further has an air inletport.

In some embodiments, the isolation barrier is arranged and configured toprovide a laminar airflow pattern through the medical procedure field.

In some embodiments, the isolation barrier has a transparent portionthrough which the medical procedure field can be viewed.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe claims that follow. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 is a perspective view of a system for creating an isolatedmedical procedure field around a subject's nose and mouth according toone embodiment of the invention.

FIG. 2 is a perspective view of the system of FIG. 1 with the isolationbarrier in place on a subject to create the medical procedure field.

FIG. 3 is a perspective view of a system for creating an isolatedmedical procedure field around a subject's nose and mouth according toanother embodiment of the invention.

FIG. 4 is a perspective view of an isolation barrier for use in a systemfor creating an isolated medical procedure field around a subject's noseand mouth according to another embodiment of the invention, in place ona subject to create the medical procedure field.

FIG. 5 is a perspective view of the isolation barrier of FIG. 4.

FIG. 6 is a perspective view of the isolation barrier of FIGS. 4 and 5showing a removable patch removed.

FIG. 7 is a perspective view of an isolation barrier for use in a systemfor creating an isolated medical procedure field around a subject's noseand mouth according to yet another embodiment of the invention, in placeon a subject to create the medical procedure field.

FIG. 8 is a perspective view of the isolation barrier of FIG. 7 showingmedical instruments being inserted into the medical procedure field.

FIG. 9 is a front elevational view of an isolation barrier for use in asystem for creating an isolated medical procedure field around asubject's nose and mouth according to yet another embodiment of theinvention, in place on a subject to create the medical procedure field.

FIG. 10 is a side elevational view of the embodiment of FIG. 9.

FIG. 11 is side sectional view of the embodiment of FIGS. 9 and 10.

FIG. 12 is a front elevational view of an isolation barrier for use in asystem for creating an isolated medical procedure field around asubject's nose and mouth according to still another embodiment of theinvention, in place on a subject to create the medical procedure field.

FIG. 13 is a perspective view of an isolation barrier for use in asystem for creating an isolated medical procedure field around asubject's nose and mouth according to another embodiment of theinvention, in place on a subject to create the medical procedure field.

FIG. 14A is a front elevational view of an isolation barrier for use ina system for creating an isolated medical procedure field around asubject's nose and mouth according to yet another embodiment of theinvention, in place on a subject to create the medical procedure field.

FIG. 14B is a perspective view of the embodiment of FIG. 14A.

FIG. 15 is a front elevational view of an isolation barrier for use in asystem for creating an isolated medical procedure field around asubject's nose and mouth according to still another embodiment of theinvention, in place on a subject to create the medical procedure field.

FIG. 16 is a perspective view of an isolation barrier for use in asystem for creating an isolated medical procedure field around asubject's nose and mouth according to another embodiment of theinvention, in place on a subject to create the medical procedure field.

FIG. 17A is a side partially sectional view of an isolation barrier foruse in a system for creating an isolated medical procedure field arounda subject's nose and mouth according to another embodiment of theinvention, in place on a subject to create the medical procedure field,showing the isolation barrier in an open position.

FIG. 17B is a side partially sectional view of the embodiment of FIG.17A showing the isolation barrier in a closed position.

FIGS. 18A and 18B illustrate an isolation barrier according to anembodiment of this invention with a linear airflow pattern through themedical procedure field.

FIGS. 19A and 19B illustrate an isolation barrier according to anotherembodiment of this invention with a linear airflow pattern through themedical procedure field.

FIGS. 20A and 20B illustrate an isolation barrier according to anembodiment of this invention with a curved airflow pattern through themedical procedure field.

FIGS. 21A and 21B illustrate an isolation barrier according to anembodiment of this invention with a converging airflow pattern throughthe medical procedure field.

FIGS. 22A and 22B illustrate an isolation barrier according to anotherembodiment of this invention with a converging airflow pattern throughthe medical procedure field.

FIGS. 23A and 23B illustrate an isolation barrier according to yetanother embodiment of this invention with a converging airflow patternthrough the medical procedure field.

FIGS. 24A and 24B illustrate an isolation barrier according to anembodiment of this invention with a diverging airflow pattern throughthe medical procedure field.

FIG. 25 illustrates an isolation barrier according to an embodiment ofthis invention with a laminar airflow pattern through the medicalprocedure field.

FIG. 26 is a side elevational view of a system for creating an isolatedmedical procedure field around a subject's nose and mouth according tostill another embodiment of the invention, in place on a subject tocreate the medical procedure field.

FIG. 27 is a block diagram showing aspects of a system for creating anisolated medical procedure field.

DETAILED DESCRIPTION

The present invention is generally directed towards systems and methodsfor creating an isolated medical procedure field using an isolationbarrier around at least a subject's nose and/or mouth and evacuating airfrom the medical procedure field at a rate equal to or greater than thesubject's respiratory minute volume to create a negative pressure in themedical procedure field. Medical procedures can be performed in andaround the subject's nose or mouth by, e.g., inserting in instrumentthrough a port of the isolation barrier or by reaching around a portionof the isolation barrier, such as a drape.

FIGS. 1 and 2 show an embodiment of a system 10 according to anembodiment of the invention. An isolation barrier 30 such as a mask maybe placed and held against the face of the subject 32 (using, e.g.,bands 34 that go around the subject's ears 36). In this embodiment,isolation barrier 30 covers the subject's nose and mouth. Edges of theisolation barrier 30 mate with the surface of the subject's face toprovide a seal, optionally using, e.g., seals 31 on the inside surfaceof the mask, to form a medical procedure field between the mask and thesubject's face. In this embodiment, the air mover is a fan in housing38. The fan connects to the interior of the isolation barrier 30 via amask outlet 35 and an outlet hose 40 of the air management system. Inthis embodiment, the fan generates volumetric flowrates at least greaterthan 10 liters/min (e.g., greater than 30 liters/min or greater than 50liters/min) so as to evacuate air from inside the isolation barrier at arate higher than the subject's exhalation rate (often defined as thesubject's “respiratory minute volume”), thereby creating a negativepressure between the inside of the isolation barrier and the subject'sface. The air mover may include a user interface 39 as well as datastorage, a control system, communication components (e.g., WiFi,Bluetooth), a controller running software, and/or a battery or otherpower source.

In the embodiment of FIGS. 1 and 2, the air mover may exhaust thefiltered air into the room after going through a filter 41, and theisolation barrier allows air in through openings 44 in the isolationbarrier, as shown by arrows 45 in FIG. 1. The number of openings 44 maybe increased to, e.g., provide laminar flow through the medicalprocedure field, as shown in FIG. 25. In the embodiment of FIG. 3, theair is filtered by a filter 41 in the outlet hose 40, (or within housing38 or within inlet hose 42), and the filtered air is returned to medicalprocedure field via an inlet hose 42 and one or more ports 44.

In these embodiments, two access ports 50 are disposed on the front ofisolation barrier 30. Access ports 50 may be formed of slits inresilient material to permit insertion of instruments and/or diagnostictool at the desired sagittal or coronal angles, seal around thoseinstruments and tools while they are being used, and seal completelyafter removal of the tools. In addition, the access ports 50 may be inone or more optional removable flaps 52 that can be opened to provide alarger access port for wider access to the subject's nose and/or mouth.When flap 52 is removed, the air flow from the air mover is sufficientlyhigh to maintain a negative pressure in the medical procedure field tocapture and remove any droplets or particulates in the subject's exhaledbreath.

The air mover is designed to produce these flowrates with minimal noisepollution having a sound rating less than 60 dBA, preferably less than50 dBA. In some embodiments, the air mover also has sensors that monitorthe system and isolation barrier. Examples of parameters that the systemwill monitor are pressure, temperature, humidity, and particulate count.The system also has ways of retrieving this data for reporting andstoring. Example of retrieving data is physical connection (e.g., USB)and/or wireless transmission (e.g., Bluetooth).

In some embodiments, the filter 41 is, for example, a one sub-micron(preferably <0.3 μm) particulate filter (e.g., HEPA, ULPA, Charcoal). Insome embodiments, the air management system has fittings and hosing thatare connectable to the isolation barrier.

In some embodiments, the exterior of the mask fits snuggly on the bridgeof the nose, the cheeks, and chin of the subject and is secured to theface by straps that go around the head or around the ears of thesubject. The apparatus contacts the nose on the lateral nasal cartilageand/or nasal bone without touching the major alar cartilage (tip of thenose) so that the tip of the nose can be manipulated (e.g., flexedupward, stretched) with nasal instruments as needed during nasalprocedures.

The sagittal angle of access area provides greater than 60 degrees(preferably greater than 70 degrees) of instrumentation movement in thesagittal plane from the base of the nostril (nasal sill) upwards andgreater than 10 degrees in either direction from the center of the nose(septum) in the coronal plane while minimizing the potential of subjectparticulates exiting the subject air environment via exhalation,sneezing or coughing. These degrees of freedom are important to allowthe physician to visualize and treat the target sites like the frontalrecess, posterior ethmoids, and the nasopharynx.

The contact points of apparatus on the chin and cheeks allow the mouthto open without losing the local barrier. In some embodiments, this isachieved by the exterior of the barrier just resting on the cheeks andchin allowing movement of the face and the high-volume evacuationflowrate prevents particulates from escaping during the movement and inother embodiments the mask is designed fit and move with the chin andcheeks as the mouth is opened and closed.

FIGS. 4-6 show another embodiment of this invention. In this embodiment,isolation barrier 60 has a clear plastic shell 62 (e.g., made frompolycarbonate, polyethylene, PVC) surrounded by a seal 63. Bands (notshown) may attach the isolation barrier to the subject's ears or goaround the subject's head to create a medical procedure field betweenshell 62 and the subject's face. The clear material of shell 62 permitsthe medical procedure field to be viewed by a healthcare provider.Various patches (such as a flat rubber patch 68 with sealable openings70) can attach to barrier 60 via a seal (e.g., gel) around an opening74.

A hose 76 leads from a port 64 in shell 62 to an air mover, such as afan (not shown). Instead of returning filtered air to the isolationbarrier, these embodiments provide air holes 78 in the isolation barrierfor the subject's inhaled air, as shown by the arrows in FIG. 4. Whenpatch 68 is removed to enable the clinician to access the medicalprocedure field through opening 74 to perform a procedure (e.g., on orin the subject's oral cavity or nasal cavity), the air flow out of port64 created by the air mover is sufficiently high to maintain a negativepressure in the medical procedure field to capture any droplets orparticulates in the subject's exhaled breath.

FIGS. 7 and 8 show another embodiment of the invention. In thisembodiment, the isolation barrier 100 includes an expandable portionthat can accommodate a sudden increase in the volume and/or momentum ofa subject's exhalation, such as from a cough or a sneeze, withoutbreaking the seal of the isolation barrier around the subject's face andthereby exposing a caregiver to aerosols in the medical procedure field.As in other embodiments, isolation barrier 100 has a clear plastic shell102 (e.g., made from polycarbonate, polyethylene, PVC) surrounded by aseal 103. Bands 105 may attach the isolation barrier to the subject'sears or go around the subject's head to create a medical procedure field101 between shell 102 and the subject's face. A hose 106 leads from aport 104 in shell 102 to an air mover, such as a fan (not shown). Airenters the medical procedure field through inlet port 108. Inlet port108 may have a filter.

A collapsible inflatable bag 110 made of thin-walled plastic film isdisposed in the shell 102. Bag 110 may expand to capture a sneeze eventand prevent a pressure increase from a sneeze or a cough from escapingthe isolation barrier. After the cough or sneeze, the negative pressurewithin the medical procedure field behind the shell 102 deflates bag 110as the exhalation, particulates, pathogens and/or aerosols are removedfrom the isolation barrier by way of the airflow outlet port 104. A slit116 in bag 110 permits the insertion of a tool 118 for performing aprocedure in the medical procedure field, as shown in FIG. 8. Bag 110may be detached from shell 102 by disconnecting connectors 112 and 114on the bag and shell, respectively, to replace the bag or to leave anopening for accessing the medical procedure field. Other embodiments mayemploy one or more of: expandable or inflatable bags; elastomericballoons; bellows; or other containment elements capable of rapidexpansion under low pressure increases in the event of an episodicevent.

FIGS. 9-11 show yet another embodiment of the invention. Isolationbarrier 200 provides a “one-size-fits-all” configuration thataccommodates a large array of facial geometries, facial hair, facialsizes, facial deformities, etc., and provides unobstructed movement ofthe jaw while preventing aerosols from escaping, so as to allow thesubject to open and close his mouth without compromising the barrierintegrity. Isolation barrier 200 has a support structure 202 withbuilt-in inflow port 204 and outflow port 206. Support structure 202 andports 204 and 206 may be injection molded. Ports 204 and 206 may beequipped with air filters to filter the air going into and coming out ofisolation barrier 200. In one optional embodiment, the ports 202 and 204may be the same size to enable the air flow conduit 208 connected to anair mover (not shown) to be placed on either side. Straps 209 attach theisolation barrier to the subject's head.

A forehead pad 210 affixed to the top of the isolation barrier and amidface pad 212 affixed to the midportion of the isolation barrier aremade of compliant material (e.g., open-cell or closed-cell foam or acompliant polymer) to provide a secure and comfortable seal around thesubject's face. The pads may be affixed via, e.g., adhesive ormechanical compression. Alternatively, the pads 210 and/or 212 may behighly compliant inflatable bladders filled with air at the time of useto conform to the subject's face. When the isolation barrier 200 isplaced on the subject's face, the forehead pad 210 makes contact andconforms to the subject's forehead and the midface pad 212 conforms tothe bridge of the nose and cheeks of the subject, as shown in FIG. 10.These pads stabilize the isolation barrier on the subject, while themidface pad additionally creates a sufficient seal on the bridge of thenose and the cheeks without contacting the anterior portion of the nose,allowing the tip of the nose move freely (such as my be required in somemedical procedures).

Isolation barrier 200 has an access window 214 adjacent to the nose andmouth. An insert 216 may be placed in window 214 to close the opening,and one or more ports 218 in insert 216 may permit the insertion oftools to perform medical procedures in the medical procedure field 220defined by the isolation barrier 200 and the subject's face. Insert 216and instrument access port(s) 218 allow access to the subject's noseand/or the mouth while preventing particulates, pathogens and aerosolsfrom escaping the medical procedure field 220 during normal breathing orduring an episodic event such as a sneeze or a cough. Insert 216 may beremoved while active airflow is being pulled from the mask giving openaccess to the nose and mouth and creating an airflow pattern serving toprevent the escape of particulates, pathogens and aerosols from escapingthe isolation barrier.

A drape 222 extends from the bottom of the support structure 202 and maybe placed against the lower part of the subject's face and around aportion of the subject's neck, as shown in FIGS. 9-11. Drape 222 may beaffixed to support structure 202 via, e.g., stitching, thermal stackingor adhesive. Drape 222 may be made of a thin flexible polymer film suchas urethane, silicone or other polymer, or of a woven or non-wovenfabric such as Tyvek or the like. The drape 222 is sized to accommodateall jaw geometries, necks, facial hair, and to be loose and baggy.Around the perimeter of the drape is an elastic band (not shown), sewninto the drape, allowing the drape to form a seal around the face andneck. This seal formed by the drape may be sufficient to prevent theexchange of airflow across it, or it may affect a partial seal only,allowing negative pressures within the medical procedure field to drawair flow through the drape seal in such a manner as to prevent theescape of particulates, pathogens and aerosols around the drape.

In one use scenario, the isolation barrier 200 is placed around thesubject's forehead, and the drape is tied around the subject's neck withthe elastic band or another attachment means. The subject is then askedto wait in the waiting room of the physician's office or otherhealthcare facility. In this passive (non-powered) state wherein theisolation barrier is not connected to an air mover, the isolationbarrier serves as a surgical mask comprising air filters on the inletand outlet air flow ports as well as the instrument access port seal tomaintain a seal. When the subject enters the exam room and sits down,the healthcare worker then attaches the air outlet conduit (that isattached to the filter, which in turn is attached to the air mover) tothe isolation barrier and turns on the air mover, starting the flow ofair. The high volumetric airflow begins replacing air inside theisolation barrier with air from the room, moving the air within theisolation barrier into the air conduit through the filter into the airmover, filtering the air and releasing it back into the room. Thehealthcare worker then begins the medical procedure by placing theinstruments through the access port breaking the seal of the port andinserting the instrument into the airway cavity. During this procedure,the aerosolization caused by the manipulation of the airway tissue iscaptured by the airflow pattern, evacuated from the isolation barrierthrough the air outlet port, passed through the airflow conduit andfiltered before allowing the air to release back into the room. Afterthe procedure is complete, the local area protection device is run forseveral minutes, allowing the air in the isolation barrier to changemultiple times. The isolation barrier is then detached from the airconduit and the subject can leave with the isolation barrier in thenon-powered state.

In some embodiments, the midface pad runs completely around the nose andthe mouth creating a seal and stabilizing the isolation barrier on thebridge of the nose, cheeks, and chin. In other embodiments, the portionof the support structure above the eyes and forehead pad are removed andthe attachment straps are affixed to the mid portion of the isolationbarrier. The forehead and midface pad depth and conformability aresufficient to accommodate various sizes of noses, foreheads, and cheekbones. The clearance range is 2 to 100 mm (preferably 30-70 mm). Thisdepth range serves to accommodate a large range of facial geometrieswhile still ensuring the isolation barrier doesn't impede instrumentaccess or prevent a healthcare worker from reaching within the nasal ororal cavity. The height range of the pads are typically between 2 mm and50 mm, allowing sufficient seal without blocking access to the nose ormouth. The pads may comprise uniform cross sectional geometry and/ordimensions, or they may vary along the length of the pads. The pads mayalso be customizable by a healthcare worker to create a custom fit tothe patient in some embodiments. In some embodiments a pocket may beformed in or affixed to the drape.

The isolation barrier systems of the invention are configured to createairflow patterns in the vicinity of the patient's face, and morespecifically in the vicinity of the patient's nose and/or mouth. Theseairflow patterns act to capture and transport normal and episodicrespiratory exhalations, as well as any associated particulates,pathogens and aerosols emitted by said patient, from the vicinity of thenose or mouth, in a controlled manner toward one or more airflow outletports, into one or more airflow conduits, and away from the isolationbarrier to be filtered and collected for later disposal.

The isolation barrier 250 in the embodiment of FIG. 12 is a modificationto the embodiment of FIGS. 9-11 that replaces the drape with a pouch 252to catch removed tissue or other debris. Pouch 252 also serves as anexpansion chamber to accommodate sudden increases in pressure and flowfrom the subject due to a cough or sneeze. Other elements of theisolation barrier remain the same and therefore retain the same elementnumbers.

The isolation barrier 270 of the embodiment of FIG. 13 extends midfacepad 212 to a region 272 that rests against the subject's chin. Like thepads 210 and 212, pad 272 may be made of compliant material (e.g.,open-cell or closed-cell foam or a compliant polymer) to provide asecure and comfortable seal around the subject's face. The pad may beaffixed via, e.g., adhesive or mechanical compression. Alternatively,pad 272 may be a highly compliant inflatable bladder filled with air atthe time of use to conform to the subject's face. When the isolationbarrier 270 is placed on the subject's face, the forehead pad 210 makescontact and conforms to the subject's forehead, the midface pad 212conforms to the bridge of the nose and cheeks of the subject, and thechin pad 272 contacts and conforms to the subject's chin, as shown inFIG. 13. These pads stabilize the isolation barrier on the subject. Theisolation barrier 270 of FIG. 13 may have an optional pouch, as in theembodiment of FIG. 12, in which case there would be an opening in pad272 to permit tissue and other debris to fall into the pouch. The otherelements of this embodiment are the same as the like-numbered elementsof the embodiments of FIGS. 9-11 and FIG. 12.

The isolation barrier 280 of the embodiment of FIGS. 14A-B is similar tothe embodiment of FIG. 13, but it omits the forehead pad and the portionof the support structure 202 extending to the forehead region. The otherelements of this embodiment are the same as the like-numbered elementsof the embodiments of FIGS. 9-11, FIG. 12 and FIG. 13.

The isolation barrier 290 of FIG. 15 is similar to that of FIGS. 14A-Bbut replaces the insert in the opening with a transparent insert 292with multiple slits 294 providing access for tools to perform medicalprocedures in the medical procedure field. (FIG. 15 shows insert 292 asopaque in order to illustrate the vertical slits 294.) The otherelements of this embodiment are the same as the like-numbered elementsof the embodiments of FIGS. 9-11, FIG. 12, FIG. 13, and FIGS. 14A-14B.

FIG. 16 shows an isolation barrier 300 that covers the entire face ofthe subject to protect both the subject and the healthcare specialistfrom exposure. The isolation barrier 300 has a clear acetate orpolycarbonate shield 340, a seal 342 around the top edge, and a foamskirt 343 at the bottom. The seals are made, e.g., of open-cell foam inthis embodiment. In other embodiments the seals are made of thinpolymeric material such as silicone, polyurethane or latex. Theisolation barrier may be held in place by band 320 that go around thesubject's ears or head. In some cases, the flat shield 340 can be bentinto a semi-cylindrical shape. In others, the shield 340 can bethermoformed into a more ergonomic configuration. A hose 344 leading toan air mover clips on to the shield to provide negative air pressurebehind the shield. The seal 342 and/or skirt 343 allow air to enterthrough the periphery of the shield, filtering out some particulate andairborne droplets. Due to the negative pressure inside the shield 340,the subject's breathing, coughing, etc., does not enter the room air,but is sucked away through the hose 344 through a HEPA filter by the airmover. When placed as shown in FIG. 16, isolation barrier 300 and thesubject's face together define a medical procedure field around thesubject's nose and mouth. Access to the medical procedure field toperform, e.g., a medical procedure in or around the oral cavity or nasalcavity is gained by means of a slit 346 in the clear portion of theshield, which can be pressed inward by the healthcare specialist tocreate an opening. When released, this slit portion pops back out to itsoriginal shape, sealing the opening in the shield 340. Alternately, theclear portion of the shield can be formed in such a way that thedeflected portion is bi-stable. When pressed inward, it stays in thatposition until pulled outward, where it then stays in the sealedposition. The isolation barrier 300 is disposable. The suction hose 344and clip can be re-used for the subsequent subjects. Periodically, theHEPA filter, suction hose 344, and coupling are replaced to ensure onlywell filtered air returns to the room environment via the air mover.

FIGS. 17A and 17B depict an isolation barrier 400 according to anotherembodiment of the invention. As in other embodiments, isolation barrier400 is used with an air conduit (not shown); a filter (not shown); andan air mover (not shown). The support structure of the isolation barrier400 is made of a clear rigid to semi-conformable polymer such aspolycarbonate or transparent polyvinyl chloride. The barrier is designedto conform to the nose, cheeks and the chin or upper neck to create aseal around the perimeter of the barrier. When the support structure ismade of a rigid polymer, a sealing component 402 is added to the outerperimeter of the isolation barrier, as described with respect to otherembodiments. On the front face of the isolation barrier adjacent to thenose and mouth there is an open access window 404 that allows thephysician free access to the nose and/or mouth of the subject with,e.g., and instrument 405. The open access window is covered with asealing flap 406 that is attached with a hinge 408 to the top of thecutout of the isolation barrier, just above the nose of the subject,proximal to, or in the vicinity of, the nasal bone allowing manipulationof the anterior portion of the nose. The sealing flap 406 is configuredto form a seal when it is in the closed position shown in FIG. 17B,effectively closing and sealing off the open access window andpreventing the release of particulates, pathogens and/or aerosols fromthe isolation barrier system. A snap or other attachment mechanism 407may hold the flap in its closed position.

Although the flap can be affixed and hinged in a variety of ways thatsomeone skilled in the art could imagine, in this embodiment, the flapis affixed using one or more tags that extends from the top of the flapthat snap into small openings in the support structure of the isolationbarrier creating hinge 408. The flap is made of a flexible rubber with amedium durometer (˜50-70 shore A). The flap is transparent ortranslucent. To allow access to the subject's nose and/or mouth, theflap may be lifted up from the sealed position, pivoting on the tophinge, and held up in the open position by the user or by one or moreinstruments 405 being used in the procedure, to allow access tosubject's nose and/or mouth. The flap 406 is configured by means ofstructure, spring, elastic deformation, magnetic elements, shape memory,and/or weight to return immediately to the closed and sealed positionwhen released.

On the sides adjacent to the hinged edge there are accordion drapes 410made of a thin flexible rubber, filter material, or other material,affixed to the flap and to the isolation barrier and configures so as tofold, in an accordion fashion, when the access flat is in the closed ansealed configuration. When the flap 406 is raised to allow access to thesubject's nose and or mouth, the drapes 410 unfold and expand in such amanner as to affect a baffle or enclosure on the two sides of theisolation barrier adjacent to the open access window. The accordion typedrapes are of sufficient flexibility so as not to inhibit the physicianduring instrument or tool manipulation.

The flap 406 can be rotated open to roughly 90 degrees or more, asmeasured from the closed and sealed position, to allow physician orhealthcare worker access to the subject's nose or mouth. In someembodiments the flap may comprise one or more instrument access ports inthe face of the transparent flap so as to provide tool access even inthe closed position.

In one use scenario, the subject enters the exam room and affixes theisolation barrier 400 onto her face, wherein the isolation barrier isinitially configured such that the flap is closed and the airflow outletport is sealed with an air filter element. The healthcare worker thenenters the room, removes the outlet air filter from the isolationbarrier, attaches the airflow conduit to the airflow outlet port,connects the other end of the airflow conduit to the air mover andstarts the isolation barrier system so as to create a desired airflowpattern and negative pressure field in and around the isolation barrier.The high volumetric airflow in the isolation barrier system beginsreplacing the air inside the isolation barrier with air from the room bymeans of the airflow input port, moving the subject's air from theisolation barrier into the air conduit by means of the airflow outputport, through the airflow conduit to the filter, through the filter,cleaning the air, into the air mover, and releasing the clean air backinto the room, preventing the unintentional release of respiratoryexhalations and associated particulates, pathogens and/or aerosols fromthe subject.

The healthcare worker then starts the exam by lifting up on the accessflap 406 (opening the access port), inserting the tip of a spray bottleinto each nostril, spraying the inside of the nose and nasal cavity withanesthetic, removing the spray bottle, and allowing the flap close andseal. During the spraying process, the airflow within the isolationbarrier is traveling at a volume flow rate and velocity that is greaterthan the respiratory exhalation rates from the subject in and around thenose and mouth, so as prevent unintended release of the subject'sexhalation into the room.

While the healthcare worker allows the anesthetic to be absorbed andtake effect, the air inside the isolation barrier is changing overconstantly, ensuring the region in front of the subject's airway isclean of the subject exhalation particulates, pathogens and aerosols.Next the healthcare worker lifts the flap using a rigid endoscope andadvances the scope into the isolation barrier. Using the other hand, thehealthcare worker follows the scope with a procedure instrument into theisolation barrier and advances the instrument into a nasal cavity. Thehealthcare worker advances both instruments into the nasal cavity andperforms the needed exam or procedure. The endoscope continues to holdthe flap open and moves against the flap keeping the access window open.

If the subject feels the imminent occurrence of an episodic respirationevent (such as a sneeze) about to happen during the procedure, thehealthcare worker can rapidly remove the instruments from the nasalcavity and from the isolation barrier, allowing the flap to close andseal the isolation barrier. During the episodic respiration event, theflap acts as a barrier catching any aerosols, particulates, pathogensand ejecta that are not captured by the airflow. Once the event is over,the healthcare worker allows the air inside the isolation barrier to beexchanged for several minutes, opens the flap, and begins the procedureagain.

FIGS. 18A-25 show how the placement of the inlet port or ports and theoutlet port or ports can affect the airflow within the medical procedurefield formed between an isolation barrier and a subject's face. In eachof these embodiments, the outlet port or ports are connected to an airmover that evacuates air from the medical procedure field formed betweenthe isolation barrier and the subject's face, and air enters the medicalprocedure field through an inlet. The inlet may be open to room air, orit may be connected to a return line from the air mover. There may befilters in one or both of the inlet and the outlet. Any of thesearrangements may be employed with any of the embodiments describedabove.

In FIGS. 18A-B, the outlet port 422 of isolation barrier 420 is at thetop, and the inlet port 424 is at the bottom. This configurationprovides a substantially linear air flow pattern within the medicalprocedure field between isolation barrier 420 and the subject's face, asshown in the transparent view of FIG. 18B.

In FIGS. 19A-19B, the inlet port 434 and the outlet port 432 are on thesides of isolation barrier 430. This configuration provides asubstantially linear air flow pattern within the medical procedure fieldbetween isolation barrier 430 and the subject's face, as shown in thetransparent view of FIG. 19B.

In FIGS. 20A-20B, the inlet port 444 is on the side of the isolationbarrier 440, and the outlet port 442 is on the top. This configurationprovides a substantially curved air flow pattern within the medicalprocedure field between isolation barrier 440 and the subject's face, asshown in the transparent view of FIG. 20B.

In FIGS. 21A-21B, there are multiple inlet ports 454 on one side of theisolation barrier 450 and one outlet port 452 on the other side. Thisconfiguration provides a substantially converging air flow patternwithin the medical procedure field between isolation barrier 450 and thesubject's face, as shown in the transparent view of FIG. 21B.

In FIGS. 22A-22B, there is a large inlet port 464 in the front of theisolation barrier 460 and one smaller outlet port 462 at the top. Thisconfiguration provides a substantially converging air flow patternwithin the medical procedure field between isolation barrier 460 and thesubject's face, as shown in the transparent view of FIG. 22B.

In FIGS. 23A-23B, there are two large inlet ports 474 at the top ofisolation barrier 470 and one small outlet port 472 at the bottom. Thisconfiguration provides a substantially converging air flow patternwithin the medical procedure field between isolation barrier 470 and thesubject's face, as shown in the transparent view of FIG. 23B.

In FIGS. 24A-24B, there is a large inlet port 484 in the front of theisolation barrier 480 and two smaller outlet ports 482 at the sides.This configuration provides a substantially converging air flow patternwithin the medical procedure field between isolation barrier 480 and thesubject's face, as shown in the transparent view of FIG. 24B.

In FIG. 25, there are multiple inlet ports 494 on one side of theisolation barrier 490 and one larger outlet port 492 on the other side.An access panel may be opened to access the medical procedure field.This configuration provides a substantially laminar flow within themedical procedure field between isolation barrier 490 and the subject'sface.

In the embodiment of FIG. 26, the isolation barrier system includes anisolation barrier 500, an air conduit 502, a filter (not shown), and anair mover 504. A support structure 506 supports a transparent ortranslucent drape 508 that, together with the subject's face, at leastpartially define a medical procedure field 509. An air inlet port 510 inthe drape leads to the medical procedure field 509, and an outlet port512 lads to air conduit 502. Air mover 504 draws air from the medicalprocedure field 509 through outlet port 512 and conduit 502 to maintaina negative pressure in the medical procedure field. The supportstructure is comprised of malleable plastic or metal rods, tubes, bars,or any other material or shape, and may be formed from a plurality ofsmall segmented rigid or semi-rigid components affixed together in amanner so as to allow safely and effectively support elements of theisolation barrier system. The transparent drape is comprised of one ormore thin film polymer elements constructed from material such asurethane, polyethylene, PVC, or any other suitable material, one or moreweights, attachments, and/or clips to keep the transparent drape in thedesired configuration during use. The drape is configured to provide aphysical barrier that covers at least the mouth and nose of a subjectand in this embodiment covers the entire front and sides of thesubject's head. The drape is affixed to the support structure. Thesupport structure creates a raised scaffolding around the subject's faceand head, and attaches to the subject's forehead and/or rests on the bedor surgical drapes around the subject's head. The transparent drape maybe sized to cover the support structure and hang down over the subject'shead and rest on the surgical bed or chair. The weight of the drape orelements within the drape keep the drape in place affecting theisolation barrier in such a manner as to prevent the subject'srespiratory exhalations and associated particulates, pathogens and/oraerosols from exiting the barrier. The air inlet and outlet ports areaffixed or built into the drape or support structure. In thisembodiment, the air inlet(s) are sewn in filtered ports positionedaround the face and the air outlet is positioned above the subject'sbetween the hairline and the tip of the nose to be out of the way of theprocedural instrumentation field and potential air breathing tubes.

In one use scenario, the isolation barrier 500 is placed over thesubject's head to form a structure similar to a tent. The supportstructure is configured to create an instrumentation access space withinthe isolation barrier, having a vertical height of at least 100 mm abovethe nasal sill and of sufficient horizontal dimensions to enable thesurgical procedure and associated tools and instruments. The drape laysover and/or affixes to the support structure and rest against thesurgical drapes placed over the subject and the surgical bed by means ofweights and/or clips. The healthcare worker then attaches the airflowconduit (that is attached to the filter that is in turn attached to theair mover) to the air outlet port and turns on the air mover. The highvolume airflow begins replacing air from inside the isolation barrierwith air from the room, moving the air within the isolation barrier intothe air conduit, through the filter, into the air mover, filtering theair and releasing it back into the room.

Once the isolation barrier system is setup, the healthcare workerreaches her gloved hands under the drape of the isolation barrier andanesthetizes the subject and intubating the subject. Once the subject isasleep, the healthcare provider begins the procedure by placing herhands under the drapes, accessing the desired airway cavity whileviewing her work through the drape. During this surgical procedure, theaerosolization caused by the manipulation of the airway tissue is beevacuated from the isolation barrier through the air outlet conduit andfiltered before allowing the air to release back into the room. Afterthe procedure is complete, the isolation barrier system is allowed torun for several minutes, allowing the air in the isolation barrier tochange multiple times. The healthcare worker then wakes up the subject,removes the breathing tube within the isolation barrier while viewingthrough the transparent drape and places a mask on the subject. Thehealthcare worked then removes her hands and allows the air to changewithin the isolation barrier for a few more minutes. After that theisolation barrier detached from the air conduit, the isolation barrieris discarded and the subject is transferred to the recovery room.

FIG. 27 is a block diagram illustrating the components of the isolationbarrier systems of this invention.

In the embodiments described herein, the air mover removes air from themedical procedure field at a rate equal to or greater than the subject'srespiratory minute volume (e.g., at an air evacuation rate greater thanor equal to 10 liters/minute). In some embodiments, the removal rate ofair from the medical procedure field creates a negative pressure in thatfield (e.g., a negative pressure of 0.14-68 cm H₂O). After the isolationbarrier is placed on a subject to form the medical procedure field,healthcare providers can perform medical procedures in, through, or onthe subject's oral and nasal cavities via the medical procedure fieldwithout being exposed to aerosols or other ejecta from the patient'sbreath.

The foregoing methods and techniques can be similarly implemented inconjunction with other medical and surgical procedures in files such asdental, periodontal, orthodontal, sinus, nasal, laryngeal, and any othernose, mouth, throat, or upper gastro-intestinal medicine, where thehealthcare professionals work in or around an upper airway cavity of apatient and may need to ensure that particles, pathogens, and/oraerosols from the patient are controlled and isolated during the medicalprocedure.

When a feature or element is herein referred to as being “on” anotherfeature or element, it can be directly on the other feature or elementor intervening features and/or elements may also be present. Incontrast, when a feature or element is referred to as being “directlyon” another feature or element, there are no intervening features orelements present. It will also be understood that, when a feature orelement is referred to as being “connected”, “attached” or “coupled” toanother feature or element, it can be directly connected, attached orcoupled to the other feature or element or intervening features orelements may be present. In contrast, when a feature or element isreferred to as being “directly connected”, “directly attached” or“directly coupled” to another feature or element, there are nointervening features or elements present. Although described or shownwith respect to one embodiment, the features and elements so describedor shown can apply to other embodiments. It will also be appreciated bythose of skill in the art that references to a structure or feature thatis disposed “adjacent” another feature may have portions that overlap orunderlie the adjacent feature.

Terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention.For example, as used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, steps, operations, elements, components, and/orgroups thereof. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items and may beabbreviated as “/”.

Spatially relative terms, such as “under”, “below”, “lower”, “over”,“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if a device in thefigures is inverted, elements described as “under” or “beneath” otherelements or features would then be oriented “over” the other elements orfeatures. Thus, the exemplary term “under” can encompass both anorientation of over and under. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly. Similarly, the terms“upwardly”, “downwardly”, “vertical”, “horizontal” and the like are usedherein for the purpose of explanation only unless specifically indicatedotherwise.

Although the terms “first” and “second” may be used herein to describevarious features/elements (including steps), these features/elementsshould not be limited by these terms, unless the context indicatesotherwise. These terms may be used to distinguish one feature/elementfrom another feature/element. Thus, a first feature/element discussedbelow could be termed a second feature/element, and similarly, a secondfeature/element discussed below could be termed a first feature/elementwithout departing from the teachings of the present invention.

Throughout this specification and the claims which follow, unless thecontext requires otherwise, the word “comprise”, and variations such as“comprises” and “comprising” means various components can be co-jointlyemployed in the methods and articles (e.g., compositions and apparatusesincluding device and methods). For example, the term “comprising” willbe understood to imply the inclusion of any stated elements or steps butnot the exclusion of any other elements or steps.

As used herein in the specification and claims, including as used in theexamples and unless otherwise expressly specified, all numbers may beread as if prefaced by the word “about” or “approximately,” even if theterm does not expressly appear. The phrase “about” or “approximately”may be used when describing magnitude and/or position to indicate thatthe value and/or position described is within a reasonable expectedrange of values and/or positions. For example, a numeric value may havea value that is +/−0.1% of the stated value (or range of values), +/−1%of the stated value (or range of values), +/−2% of the stated value (orrange of values), +/−5% of the stated value (or range of values), +/−10%of the stated value (or range of values), etc. Any numerical valuesgiven herein should also be understood to include about or approximatelythat value, unless the context indicates otherwise. For example, if thevalue “10” is disclosed, then “about 10” is also disclosed. Anynumerical range recited herein is intended to include all sub-rangessubsumed therein. It is also understood that when a value is disclosedthat “less than or equal to” the value, “greater than or equal to thevalue” and possible ranges between values are also disclosed, asappropriately understood by the skilled artisan. For example, if thevalue “X” is disclosed the “less than or equal to X” as well as “greaterthan or equal to X” (e.g., where X is a numerical value) is alsodisclosed. It is also understood that the throughout the application,data is provided in a number of different formats, and that this data,represents endpoints and starting points, and ranges for any combinationof the data points. For example, if a particular data point “10” and aparticular data point “15” are disclosed, it is understood that greaterthan, greater than or equal to, less than, less than or equal to, andequal to 10 and 15 are considered disclosed as well as between 10 and15. It is also understood that each unit between two particular unitsare also disclosed. For example, if 10 and 15 are disclosed, then 11,12, 13, and 14 are also disclosed.

Although various illustrative embodiments are described above, any of anumber of changes may be made to various embodiments without departingfrom the scope of the invention as described by the claims. For example,the order in which various described method steps are performed mayoften be changed in alternative embodiments, and in other alternativeembodiments one or more method steps may be skipped altogether. Optionalfeatures of various device and system embodiments may be included insome embodiments and not in others. Therefore, the foregoing descriptionis provided primarily for exemplary purposes and should not beinterpreted to limit the scope of the invention as it is set forth inthe claims.

The examples and illustrations included herein show, by way ofillustration and not of limitation, specific embodiments in which thesubject matter may be practiced. As mentioned, other embodiments may beutilized and derived there from, such that structural and logicalsubstitutions and changes may be made without departing from the scopeof this disclosure. Such embodiments of the inventive subject matter maybe referred to herein individually or collectively by the term“invention” merely for convenience and without intending to voluntarilylimit the scope of this application to any single invention or inventiveconcept, if more than one is, in fact, disclosed. Thus, althoughspecific embodiments have been illustrated and described herein, anyarrangement calculated to achieve the same purpose may be substitutedfor the specific embodiments shown. This disclosure is intended to coverany and all adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the above description.

What is claimed is:
 1. A method of performing a procedure in or around asubject's nose or mouth, the method comprising: evacuating air from amedical procedure field adjacent to the subject's nose and mouth at anair evacuation rate greater than or equal to the subject's respiratoryminute volume, the medical procedure field being bordered at leastpartially by a face of the subject and an isolation barrier disposedagainst the face of the subject, the isolation barrier controlling airflow into the medical procedure field, the isolation barrier comprisingan expandable portion adapted to accommodate a sudden increase in volumeor momentum of an exhalation of the subject; expanding the expandableportion to accommodate a cough or a sneeze of the subject; and accessingthe subject's nose or mouth within the medical procedure field throughan opening in the expandable portion of the isolation barrier to performthe procedure.
 2. The method of claim 1 wherein the air evacuation rateis greater than or equal to 10 liters/minute.
 3. The method of claim 1further comprising maintaining a negative pressure within the medicalprocedure field.
 4. The method of claim 3 wherein the negative pressureis 0.14-68 cm H₂O.
 5. The method of claim 3 further comprisingmaintaining the negative pressure within the medical procedure fieldwhen the subject coughs or sneezes.
 6. The method of claim 1 wherein theisolation barrier comprises a transparent portion through which themedical procedure field can be viewed, the method further comprisingviewing the subject's nose or mouth through the transparent portion ofthe isolation barrier.
 7. The method of claim 1 further comprisingfiltering air evacuated from the medical procedure field.
 8. The methodof claim 1 wherein the accessing step comprises inserting an instrumentthrough a port in the isolation barrier.
 9. The method of claim 8wherein the inserting step comprises inserting the instrument through aseal of the port.
 10. The method of claim 1 further comprising deflatingthe expandable portion after the expanding step.
 11. The method of claim1 wherein the isolation barrier further comprises a face componentadapted to engage the subject's face and to at least partially surroundthe subject's nose and mouth, the method further comprising detachingthe expandable portion from the face component after the accessing step.12. A method of performing a procedure in or around a subject's nose ormouth, the method comprising: evacuating air from within an isolationbarrier at least partially defining a medical procedure field adjacentto the subject's nose and mouth at an air evacuation rate greater thanor equal to the subject's respiratory minute volume, the isolationbarrier being engaged with the subject's face surrounding the subject'snose and mouth, the isolation barrier comprising an expandable portionadapted to accommodate a sudden increase in volume or momentum of anexhalation of the subject; expanding the expandable portion toaccommodate a cough or a sneeze of the subject; and accessing thesubject's nose or mouth within the medical procedure field through anopening in the expandable portion of the isolation barrier to performthe procedure.
 13. The method of claim 12 wherein the air evacuationrate is greater than or equal to 10 liters/minute.
 14. The method ofclaim 12 further comprising maintaining a negative pressure within themedical procedure field.
 15. The method of claim 14 wherein the negativepressure is 0.14-68 cm H₂O.
 16. The method of claim 14 furthercomprising maintaining a negative pressure within the medical procedurefield when the subject coughs or sneezes.
 17. The method of claim 12wherein the isolation barrier comprises a transparent portion throughwhich the medical procedure field can be viewed, the method furthercomprising viewing the subject's nose or mouth through the transparentportion of the isolation barrier.
 18. The method of claim 12 furthercomprising filtering air evacuated from the medical procedure field. 19.The method of claim 12 wherein the accessing step comprises inserting aninstrument through a port in the isolation barrier.
 20. The method ofclaim 19 wherein the inserting step comprises inserting the instrumentthrough a seal of the port.
 21. The method of claim 12 furthercomprising deflating the expandable portion after the expanding step.22. The method of claim 12 wherein the isolation barrier furthercomprises a face component adapted to engage the subject's face and toat least partially surround the subject's nose and mouth, the methodfurther comprising detaching the expandable portion from the facecomponent after the accessing step.
 23. A method of performing aprocedure in or around a subject's nose or mouth, the method comprising:evacuating air from a medical procedure field adjacent to the subject'snose and mouth to create a negative pressure within the medicalprocedure field, the medical procedure field being bordered at leastpartially by a face of the subject and an isolation barrier disposedagainst the face of the subject, the isolation barrier controlling airflow into the medical procedure field; expanding an expandable portionof the isolation barrier to accommodate a cough or a sneeze of thesubject; and accessing the subject's nose or mouth within the medicalprocedure field through an opening in the expandable portion to performthe procedure.
 24. The method of claim 23 wherein the negative pressureis 0.14-68 cm H₂O.
 25. The method of claim 23 further comprisingmaintaining the negative pressure within the medical procedure fieldwhen the subject coughs or sneezes.
 26. The method of claim 23 whereinthe isolation barrier comprises a transparent portion through which themedical procedure field can be viewed, the method further comprisingviewing the subject's nose or mouth through the transparent portion ofthe isolation barrier.
 27. A method of performing a procedure in oraround a subject's nose or mouth, the method comprising: evacuating airfrom within an isolation barrier at least partially defining a medicalprocedure field adjacent to the subject's nose and mouth to create anegative pressure within the medical procedure field, the isolationbarrier being engaged with the subject's face surrounding the subject'snose and mouth; expanding an expandable portion of the isolation barrierto accommodate a cough or a sneeze of the subject; and accessing thesubject's nose or mouth within the medical procedure field through anopening in the expandable portion to perform the procedure.
 28. Themethod of claim 27 wherein the negative pressure is 0.14-68 cm H₂O. 29.The method of claim 27 further comprising maintaining the negativepressure within the medical procedure field when the subject coughs orsneezes.
 30. The method of claim 27 wherein the isolation barriercomprises a transparent portion through which the medical procedurefield can be viewed, the method further comprising viewing the subject'snose or mouth through the transparent portion of the isolation barrier.31. A method of performing a procedure in or around a subject's nose ormouth, the method comprising: evacuating air from within an isolationbarrier at least partially defining a medical procedure field adjacentto the subject's nose and mouth to create a negative pressure within themedical procedure field, the isolation barrier comprising an expandableportion adapted to accommodate a sudden increase in volume or momentumof an exhalation of the subject and a face component adapted to engagethe subject's face and to at least partially surround the subject's noseand mouth, the isolation barrier controlling air flow into the medicalprocedure field; accessing the subject's nose or mouth within themedical procedure field through the expandable portion to perform theprocedure; and detaching the expandable portion from the face componentafter the accessing step.
 32. The method of claim 31 wherein thenegative pressure is 0.14-68 cm H₂O.
 33. The method of claim 31 furthercomprising maintaining the negative pressure within the medicalprocedure field when the subject coughs or sneezes.
 34. The method ofclaim 31 wherein the isolation barrier comprises a transparent portionthrough which the medical procedure field can be viewed, the methodfurther comprising viewing the subject's nose or mouth through thetransparent portion of the isolation barrier.
 35. A method of performinga procedure in or around a subject's nose or mouth, the methodcomprising: evacuating air from within an isolation barrier at leastpartially defining a medical procedure field adjacent to the subject'snose and mouth to create a negative pressure within the medicalprocedure field, the isolation barrier comprising an expandable portionadapted to accommodate a sudden increase in volume or momentum of anexhalation of the subject and a face component adapted to engage thesubject's face and to at least partially surround the subject's nose andmouth; accessing the subject's nose or mouth within the medicalprocedure field through the expandable portion to perform the procedure;and detaching the expandable portion from the face component after theaccessing step.
 36. The method of claim 35 wherein the negative pressureis 0.14-68 cm H₂O.
 37. The method of claim 35 further comprisingmaintaining the negative pressure within the medical procedure fieldwhen the subject coughs or sneezes.
 38. The method of claim 35 whereinthe isolation barrier comprises a transparent portion through which themedical procedure field can be viewed, the method further comprisingviewing the subject's nose or mouth through the transparent portion ofthe isolation barrier.